Valve geak foe steam engines



(N0 Model.) 4 She'ets-Sheet ,l.

M. N. LYNN.

VALVE GEAR FOR STEAM ENGINES.

N0. 313,00.'7. PatentedFeb. 24, 1885.

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LYNN. a VALVE GEAR P03 STEAM ENGINES. 1 No. 313,007. Patented Feb. 24,1885. x a 7 \i Ziinesses I [71 we 2 7m %WMMM L 1 W Q (No Model.) 4Sheets-Sheet s. I

M. N LLYNN.

- VALVE GEAR FOR. STEAM "ENGINES. No. 313,007. Patented Feb. 24, 1885.

minesses MM QM 4 sheets Sheet 4.

(No Model.) 1 v M. N. LYNN.

VALVE GEAR'FOR STEAM ENGINES.

Patented Peb. Z4,1885.

llllllllllllflll N. PEl'ERS. Phnlo-Liihngnphnr. Wnhinginm 0.1:.

UNTTED STATES MIRABEAU N. LYNN, or RISING sUN,

ASSIGNOR, BY MESN-E ASSIGNMENTS,

TO THE AMERICAN ELECTRIC HEADLIGHT'COMPANY, OF INDIANAPOLIS,

INDIANA.

VALVE-GEAR FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 313,007, dated February24, 1885.

Application filed April 10, 1884. (No model T to whom it may concern.-

Be it known that I, MIRABEAU N. LYNN, of Rising Sun, in the county ofOhio and State of Indiana, have invented certain new and usefulImprovements in Valve-Gear for Steam- Engines; and I do hereby declarethe following to be a full, clear, and exact description of the same,reference being had to the accompanying drawings, forming a part of thisspecification, and to the figures and letters of reference markedthereon.

My invention has for its object to provide a powerful engine capable ofbeing run at ahigh rate of speed with the consumption of a minimumamount of steam; and to this end it consists in the novel constructionof an engine of the three-cylinder type, which will be hereinafter fullydescribed and claimed.

In the accompanying drawings of my en- 2 gine, Figure 1 represents atransversesectional elevation. Fig. 2 isalongitudinal sectionalelevation; Fig. 2, a detail view of amodification ofthe speeding-upgearing; Fig.3, atransverse section on the line 1 1, Fig. 2; Fig. 4, a

2 5 transverse section on the line 22, Fig. 2; Fig. 5, a transversesection on the line 3 3, Fig. 2; Fig. 6, a transverse section on theline 4 4, Fig. 2; Fig. 7, a transverse section on the line 5 5, Fig. 2;Fig. 8, a detail view showing a 3:) modification of the exterior bearingof the engine-shaft; Fig. 9, a detail view showing the relativepositions of v the fixed and movable eccentrics of the valve-gearing.Figs. 10 and 11 are views illustrating a form of compensating-springadapted to be applied to weighted arms of the cutoff regulator.

Similar letters of reference in the several figures indicate the sameparts.

The letter A indicates the main shaft of the 0 engine, supported so asto freely revolve in an inner fixed bearing, B, provided within the maincasing G and in an outer sleeve-bearing, D, sustained bya standard, E,as shown.

Keyed to the inner end of the main shaft A is a weighted crank arm orblock, F, provided with a crank-wrist, G, as shown in Fig. 1. This wristprojects through an opening, h, arranged about centrally of a yoke orframe, H,

and to the latter are connected the pitmen or connecting-rods I J K ofthree'pistons, l J K, working in three independent cylinders, I? J Krespectively, as also shown in Fig. 1. A series of friction-rollers, h,three or more in number, suitably mounted between the two plates ofwhich the yoke or frame H is composed, and projecting into the openingh, through which the crank-wrist passes, serve as the bearings of theyoke upon the wrist. The'inner end of the pitman I is firmly secured tothe yoke I-l, preferably by a screw-' connection, while its outer end isjoined to the piston I, being secured by means of a strap, 73, andadjusting-wedges i, as shown. By reason of the yoke being fixed to theinner end of the pitman I, the latter operates to prevent it fromturning laterally, and always insures the proper relation ofitsfriction-bearings with respect to the crank-wrist. The pitman J is notonly jointed to its piston, but is also jointed at its inner end to theyoke, and the same is true of the pitman K. I prefer to form the jointedconnections of these two lastnamed pitmen by concaving both ends of eachof the rods and fitting them to cross-boltsupon the piston and yoke,respectively, and then applying a separate strap, it, around each of thebolts and bringing both of the straps together and securing them byscrew-bolts k 70, or other suitable means. This construction is foundvery desirable, as it enables both of the bearings of each pitman to besimultaneously tightened or loosened by a manipulation of thescrew-bolts, and to maintain their positions of adjustment until, fromwear ofthe parts or oth er cause, it becomes necessary to change them.The several pistons are properly packed, so as to closely fit theirrespective cylinders. Adjoining each piston-cylinder is arranged avalve-cylinder, L, having at its upper end a port or passage, 1, leadingdirectly to the boiler or source ofsteam-supply, and having also belowthe port Z a series of other passages, Z, all communicating with anannular passage, Z whichin turn communicates with the upper end of theadjoining piston-cylinder by a port or passage, Z. Each of the valves Lis connected to a rod or stem, M, which is centered by, but works freelythrough, a guide N, arranged at the lower end of the valve-cylinder, asshown, but offering no material obstruction to the passage of theexhaust-steam out through the said lower end of the valve-cylinder, aswill be further on explained. Each valve-rod is provided at its innerend with a friction-roller, 0, which bears upon two eccentrics, Qand R,on the main engine'shaft A, as shown in Figs. 2 and 9. The eccentric Qis keyed rigidly to the shaft A, and always sustains the same relationto it; but the eccentric R, though conforming in slope to the eccentricQ, and normally arranged to exactly coincide with it in position, iskeyed to a sleeve, S, mounted loosely uponthe shaft, said sleeve havingformed with it or secured to it a pinion, P, with which engage twogear-sections, T T, secured, respectively, to the inner ends oftwoindependent shafts,f f, which have bearings in opposite ends of across-bar, T, secured rigidly to the shaft Aby a screw, f, as shown inFig. 2, or otherwise. Upon the opposite end of each of the shafts f issecured a curved arm, f, which carries at its outer end a weight.

2 f. Each of the curved armsf is so shaped as to extend fromits point ofconnection with the shaft 25 around and to the opposite side of the mainshaft A, so that the weight carried by it will stand in a positionexactly opposite to the weight carried by the other curved arm, one ofthe weights being provided with a curved slot, f, to accommodate theshaft f of the opposite curved arm, as shown clearly in Figs. 3 and 4:.A spiral spring, f, is secured at one end to each of the curved armsfand at the opposite end to the fixed cross-bar T, for the purpose ofoperating to normally hold the arms and the weight in the position shownin Figs. 3 and 4.

The pistons and connecting-rods of the several cylinders are so adjustedwith relation to the yoke or frame H, by which power is applied to thecrank on the main shaft, and also with relation to the valves,valve-rods, and operating-eccentrics, that, when one cylinder begins totake steam, the second cylinder will be working under fullsteam-pressure, while the third cylinder will be exhausting. When eitherof the cylinders is taking steam, the valve in the correspondingvalve-cylinder is drawn inward, so as to permit the steam to enter theinlet-port Z under full boiler-pressure and pass directly through thepassages Z Z l intothe cylinder, and there operate upon the piston withfull force, the motion of the piston being transferred, through thepitman, connecting-yoke, and crank, to the main eugine shaft A andcausing the rotation of the latter. As the piston of either cylindernears the end of its stroke, the fixed cam Q, on the main shaft,operating upon the roller on the inner end of the appropriatevalve-stem, causes the valve to be thrust out till it passes the portsZ, thus cutting off the steam from the cylinder and permitting thatremaining in the cylinder to exhaust out through the passages Z and Zand through the open valve-cylinder into the main casing O, lubricatingall the parts located therein, and finally escaping through a passage,0, as shown in Fig. 2. The arrangement of the valves is such that thereis always an inward pressure of steam upon them, which causes therollers upon the'inner ends of their stems to bear at all timesuniformly upon the operating-eccentrics, and to run smoothly and evenlythereon without noise or jarring.

A clear idea of the action of the three pistons in co-operatively givingmotion to the main engine'shalt may be gathered from in spectiou ofFig. 1. Here the piston I in cylinder I isjus't commencing to takesteam, the piston J in cylinder J'is operating under fullsteam-pressure, while thepiston K in cylinder K has just completed itsinward movement and is moving outward, the exhaust steam passing out infront of it. During the entire operation of the engine the whole powerof one piston and more or less than a half of the power of one of theother pistons under full boiler-pressure is exerted upon the main shaft,giving the latter very rapid and powerful rotation.

Vhile the engine is running ata normal rate of speech-the weighted armsf f under the influence of the springs f f remain in substantially theposition shown in Figs. 8 and 4, and both eccentrics Q and It operateuniformly and together upon the valve-stems and effect the periodicopening and closing of the valves. W'hen, however, the speed of theengine is increased above the normal rate, the centrifugal force of theweighted arms overcomes the tension of the actuating-springs and causesthe arms to be thrown outward, and the shafts'ff, upon which they aremounted, to turn in their bearings. As the shaftsff turn, thegear-sectors T, connected to them, are also turned, and, operating uponthe pinion P of the sleeve S, cause the sleeve and the attached cam R tobe moved more or less out of center with the fixed cam Q, so as to bringsaid movable cam It into position to more or less quickly return thevalves into position to close the ports Z, after the steam has beenadmitted through said ports to the respective pistoncylinders, and keepsaid ports closed, while the steam in the piston-cylinders is operatingupon the pistons by its expansive force only. In this way the movableeccentric and its connections are made instrumental in regulating andgoverning the speed of the engine, as well as in economizing steam. Thediagram, Fig. 9, will serve to illustrate this feature of my inventionmore clearly. The fixed eccentric is represented in full lines and themovable eccentriein dotted lines. Of the three valvesshown, let the onemarked M represent the valve to be operated upon. \Vhile the engine isrunning at a normal rate of speed, the fixed eccentric will cause thevalve M to admit steam into the cylinder when the point a of theeccentric is under the valve-stem, and to commence the exhaust when thepoint e is under said stem.

on the arm f which is opposite.

Upon the speed of the enginebeing increased, I completely automaticmanner, and saving however, the shifting of the movable eccentric intothe position represented by the dotted lines will obviously cause themovement of the valve in the direction of the exhaust to be acceleratedup to point where the valve covers the ports leading from thepiston-cylinder, where the valve will retard till the steam in thecylinder shall have had time to operate upon the piston by expansion,and then the exhaust movement will be continued until the exhaust-portsare wholly opened by the fixed eccentric.

In place of the spiral spring f, I may, and preferably do, employ acompensating-spring arrangement, such as shown in Figs. 10 and 11. Toprovide such, the cross-bar T is formed with an elongated hub, T", whichextends along the main shaft under the weighted armsf f Opposite each ofsaid weighted arms the said hub is provided with short lugs 'I T, and toeach of these lugs is connected a small spirallygrooved conical pulley,'1, connected at one end to a helical spring, T the other end of thesaid spring being fixed to the lug. A

chain, T, is fastened to the longest end of the pulley, and extendsthence to the weight When the weighted arms are in their normalpositions, the chains T are wound up on their respective spiral pulleys,from the larger to the smaller part of said pulleys, by the action ofthe helical springs; but, as the weighted arms are thrown out bycentrifugal force, the chains are unwound, and, as the unwindingproceeds, the leverage exerted by the chains on the larger parts of thepulleys overcomes the tension of the helical springs to such an extentas to diminish the resistance to the outward throw of the arms inproportion to the extent of such throw, and thus render the contrivancemore sensitive than if there w ere a direct application of simplesprings which increased in force as they were stretched,

Rigidly keyed to the main shaft A within the casing O is a gear-wheel,V, with which meshes a pinion, V, fixed to a short shaft, V, having itsbearings in the casing G. On the outer end of the shaft V is fixedanother pinion, V, which meshes with a gearwheel, V, secured to atubular shaft or sleeve, V This tubular shaft V is provided at its innerend with three (more or less) frictional rollers, V, which bear upon themain shaft A, and serve as well to center as to support the inner end ofsaid tubular shaft, while at its outer end said tubular shaft hasconnected to it the cap or bearing D, before referred to as constitutingthe outer sleeve-bearing of the main shaft. The exhaust steam, carrying,as

it does, in the form of vapor, the lubricatingoil fed in with thesteam-supply, is discharged into the casing G, and, having access to allthe operative parts of the machinery therein located, keeps them, aswell as the bearings between the main shaft and tubular shaft, all

the time thoroughly lubricated in the most much time and specialattention on the part of the engineer.

Instead of locating the pinion V and gearwheel V* outside of the casing.as shown in Fig. 2. I, by preference, arrange them both, as well as thepinion V, within the casing, as shown in Fig. 2, so that all of thegears may have the advantage of the lubricating and noise-deadeningeffects due to their operation in the exhaust-steam of the engine.

The power of the engine may be applied through the instrumentality of apulley fixed to the tubular shaft V and utilized for any desiredpurpose; but, as I have especially-designed my engine for the driving ofa dynamoelectric machine, it is perhaps best adapted for that use, thearmature of the dynamo being mounted upon, so as to turn with, thehollow shaft V In order to get the best effects from a dynamo-machine,it is necessary that it be run at an exceedingly high velocity, and,from the difficulty experienced in'getting an engine that could run withspeed enough to perform the work required, all attempts at directapplication of steam-engines to dynamos have hitherto been unsuccessful.

All these things I have had in View in the production of my invention;and to that end I have so balanced and inclosed the operative parts ofthe machinery, and provided for the using steam at nearly or quiteboiler temperatu re, as to enable the main shaft A to be given a normalrotation of about six hundred turns per minute; and then I have sogeared up the tubular shaft upon which the armature of the dynamo is tobe mounted as to impart tothe latter about twelve hundred revolutions aminute, and have thus, I think, succeeded in making a practicalimprovement in the art of electric lighting.

I intend, among other applications of my engine, to mount it and itsaccompanying dynamo upon the boiler of a railway-locomotive fortrain-lighting, taking steam directly from the locomotive-boiler.

No special attention is to be given to the engine after once being setup and adjusted, the engineer being able to start or stop it by simplyturning on or off the steam-supply from his position in the cab. v

In order to decrease friction in the outer bearings of the main andtubular shafts, I preferably, in lieu of the construction shown in Fig.2, employ that shown in Fig. 5, wherein the main shaft is given aseparate bearing in the standard E, and the tubular shaft is providedwith friction-rollers, which bear upon the main shaft, the same as atthe inner end of the said tubular shaft, as before described.

The con'ibina-tion and arrangement of the crank-0perating mechanism,driving-gears, c linders, and main casing, as shown and described, formthe subject-niatter of a prior application, filed January 10, 1884, No.117,018, of which this application is a division, and

such matters are therefore herein disclaimed, the present inventionappertaining to the valve-operating mechanism only.

I claim as my invention 1. The combination, with the val vcs, of theeccentric fixed to the main shaft, the movable eccentric, and means forchanging the position of the movable eccentric when the speed of themain shat'tincreases above the normal rate, so as to move saidecccntricto operateindependently upon the valves and cause them to cutoff the steam in the cylinders and allow it to work by expansion only,substantially in the manner described.

2. The combination, with the main shaft and valve-rod, of the movableeccentric mounted on the sleeve, the pinion on the sleeve, thegear-sectors and their shafts and shaft-sup l ports, and the weightedarms, substantially as resistance oi'fe red to the outward movement of30 the weighted arms in proportion to the extent of such outwardmovement, substantially as described.

Witnesses: MIRABEAU N. lllfitlqhl.v

A. S. STEUART, FRED F. CHURCH.

